Indium-111-labeled platelets: effect of heparin on uptake by venous thrombi and relationship to the activated partial thromboplastin time

Journal Article · Wed Sep 01 04:00:00 EDT 1982 · Circulation; (United States)

DOI:https://doi.org/10.1161/01.CIR.66.3.632· OSTI ID:5985901

Fedullo, P F; Moser, K M; Moser, K S; Konopka, R; Hartman, M T

The goal of heparin thepapy in deep vein thrombosis is to prevent thrombus extension. The relationship between thrombus extension and the results of coagulation tests used to monitor heparin thepapy is unclear. To expose this relationship, we studied the effect of several heparin regimens on the accretion of indium-111-labeled platelets on fresh venous thrombi, as detected by gamma imaging, and monitored the activated partial thromboplastin time (APTT). Six dogs were treated with a 300-U/kg bolus of heparin followed by a 90-U/kg/hour heparin infusion, a dose of heparin sufficient to increase the APTT to levels greater than eight times baseline (APTT ratio); platelet accretion (thrombus imaging) occurred only after the heparin effect was reversed with protamine sulfate. Nineteen dogs were treated with a 150-U/kg bolus of heparin followed by a 4-hour, 45-U/kg/hour heparin infusion; a thrombus was demonstrated only after protamine injection in 12 (mean APTT ratio 1.3 +/- 0.19) and before protamine injection in seven. In thirteen of these 19 dogs, 30 minutes separated the platelet injection from heparin therapy, while in six this duration was less than 30 minutes. In four of these six dogs, thrombi were demonstrated before protamine therapy and at APTT ratios greater than 3.0. Finally, 10 dogs were treated with a 100-U/kg bolus followed by a 3-hour, 50-U/kg/hour heparin infusion, after which the APTT was allowed to return to baseline values spontaneously. In all 10 dogs, a thrombus was demonstrated only after cessation of the heparin infusion, and at a mean APTT ratio of 1.4 +/- 0.15 times baseline. These results suggest that, except with very early platelet injection, platelet accretion by thrombi is consistently inhibited by heparin at APTT ratios greater than 2.5.

• Research Organization: Univ. of California Medical Center, San Diego
• OSTI ID: 5985901
• Journal Information: Circulation; (United States), Journal Name: Circulation; (United States) Vol. 66:3; ISSN CIRCA
• Country of Publication: United States
• Language: English

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62 RADIOLOGY AND NUCLEAR MEDICINE
AMINES
ANIMALS
ANTICOAGULANTS
BETA DECAY RADIOISOTOPES
BIOLOGICAL ACCUMULATION
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BLOOD COAGULATION FACTORS
BLOOD PLATELETS
BODY FLUIDS
CAMERAS
CARBOHYDRATES
CARDIOVASCULAR DISEASES
COAGULANTS
DAYS LIVING RADIOISOTOPES
DIAGNOSIS
DISEASES
DOGS
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
GAMMA CAMERAS
HEMATOLOGIC AGENTS
HEMOSTATICS
HEPARIN
HEPARIN ANTAGONISTS
IMAGES
INDIUM 111
INDIUM ISOTOPES
INHIBITION
INJECTION
INTAKE
INTERMEDIATE MASS NUCLEI
INTRAVENOUS INJECTION
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LABELLING
MAMMALS
MATERIALS
MINUTES LIVING RADIOISOTOPES
MUCOPOLYSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
POLYSACCHARIDES
PROTAMINES
PROTEINS
RADIOISOTOPES
SACCHARIDES
THERAPY
THROMBOPLASTIN
THROMBOSIS
TRACER TECHNIQUES
VASCULAR DISEASES
VERTEBRATES